About 1% of the EU population suffers from coeliac disease
Some people have an adverse reaction to the protein in wheat flour, when it is eaten. The problem mainly affects people who have coeliac disease, which is associated with wheat gluten. It is estimated that about 1% of the EU population suffers from coeliac disease, although the majority of this 1% do not have a formal diagnosis.
Wheat allergy or intolerance
Other adverse reactions to wheat are quite rare too. The evidence suggests that consumers over-estimate food allergies and intolerances by a factor of 10, meaning the prevalence is ten times less than it is perceived.
If an allergy is suspected standardised tests should be used for diagnosis. In contrast with food allergy, food intolerance does not involve the immune system. The exact mechanism of food intolerance is unclear in some cases, such as intolerance to wheat. Unlike food allergy, the symptoms of food intolerance tend to occur after a longer period of time, are usually less severe than food allergy and in most cases require ingestion of larger amounts of food than food allergy.
In any case, unnecessary wheat avoidance may lead to inadequate intakes of key nutrients and fibre over the long-term.
The EU legislation, in its Directive 2003/89/EC, requires the clear labelling of food allergens so that sufferers can avoid foods to which they are allergic. Wheat, wheat flour and gluten should all be clearly labelled when they are present in foods.